MOSCOW, Kan. (AP) – Crews in southwest Kansas are trying to salvage at least some hay from a fire that has burned thousands of bales so far.

About 51,000 bales owned by Abengoa Bioenergy and Cattle Empire have been burning since May 28 near Moscow in Stevens County.

Fire Chief Darroll Munson told the Garden City Telegram that nearly 18,000 additional hay bales may be saved. Munson said crews made progress on the blaze over the weekend and expected have the entire fire extinguished in the coming days.

Stevens County officials were assisted by crews from surrounding counties and communities, including three neighboring agencies from Oklahoma.

Investigators have not determined a cause of the fire but suspect that lightning may be the culprit.